scholarly journals Improve the Detection Range of Semi-Active Laser Guidance System by Temperature Compensation of Four-Quadrant PIN Detector

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2284 ◽  
Author(s):  
Siyuan Gao ◽  
Hui Liu ◽  
Hongwei Zhang ◽  
Xin Zhang ◽  
Juan Chen
Keyword(s):  
Ambient Temperature ◽  
Temperature Stress ◽  
Temperature Compensation ◽  
Signal To Noise Ratio ◽  
Guidance System ◽  
Laser Guidance ◽  
Detection Range ◽  
Factors Affecting ◽  
Active Laser ◽  
Four Quadrant

The detection range of a semi-active laser guidance system can deviate significantly from the design value over a wide ambient temperature range. In this paper, a mathematical model of the detection range of a semi-active laser guidance system is built and the main factors affecting the detection range are analyzed. The parameter responsivity, which shows significant change, is found by applying the ambient temperature stress to the four-quadrant PIN detector and its signal processing chain. The relationship between the maximum detection range and ambient temperature is established based on a given signal-to-noise ratio, which is necessary for reliable detection. The target temperature and tolerance are setup for real-time temperature compensation for the four-quadrant PIN detector. The ambient temperature stress is applied to the system under compensation to verify the effect of compensation. The experimental results show that the ratio of the maximum variation of the detection range to the design point is 6.9% after the compensation is implemented when the ambient temperature changes from −40 °C to 60 °C, which is improved by 13.2% compared to that without compensation.

Development of laser guidance system for UAV

2021 ◽  
Vol 2021.59 (0) ◽  
pp. 10a1
Author(s):  
Naoki KAMIO ◽  
Masafumi MIWA ◽  
Yusuke TAKEUCHI
Keyword(s):  
Guidance System ◽  
Laser Guidance

scholarly journals Comparative investigations of nonlinear and linear observers for a highly manoeuvrable target in sliding mode guidance

2017 ◽  
Vol 65 (2) ◽  
pp. 233-245
Author(s):  
Y. Wang ◽  
M. Sun ◽  
S. Du ◽  
Z. Chen
Keyword(s):  
Sliding Mode ◽  
Guidance System ◽  
Key Factors ◽  
Factors Affecting ◽  
First Order ◽  
Guidance Law ◽  
Linear Observer ◽  
Overall Performance ◽  
Twisting Algorithm ◽  
Different Levels

Abstract Target manoeuvre is one of the key factors affecting guidance accuracy. To intercept highly maneuverable targets, a second-order sliding-mode guidance law, which is based on the super-twisting algorithm, is designed without depending on any information about the target motion. In the designed guidance system, the target estimator plays an essential role. Besides the existing higher-order sliding-mode observer (HOSMO), a first-order linear observer (FOLO) is also proposed to estimate the target manoeuvre, and this is the major contribution of this paper. The closed-loop guidance system can be guaranteed to be uniformly ultimately bounded (UUB) in the presence of the FOLO. The comparative simulations are carried out to investigate the overall performance resulting from these two categories of observers. The results show that the guidance law with the proposed linear observer can achieve better comprehensive criteria for the amplitude of normalised acceleration and elevator deflection requirements. The reasons for the different levels of performance of these two observer-based methods are thoroughly investigated.

scholarly journals Research on Temperature Compensation Method in Crankshaft Online Measurement System

2021 ◽  
Vol 11 (16) ◽  
pp. 7558
Author(s):  
Tingting Gu ◽  
Xiaoming Qian ◽  
Peihuang Lou
Keyword(s):  
Ambient Temperature ◽  
Measurement System ◽  
Temperature Compensation ◽  
Compensation Method ◽  
Displacement Sensor ◽  
Online Measurement ◽  
High Precision Measurement ◽  
Temperature Changes ◽  
Dragonfly Algorithm ◽  
Measuring Machine

The crankshaft online measurement system has realized the full inspection function with fast beats, at the same time it requires for high-precision measurement. Considering the effect of ambient temperature and temperature changes on measuring machine, the calibration part, the measured crankshaft and displacement sensor, a temperature compensation method is proposed. Firstly, relationship between calibration part and ambient temperature can be get through the zero calibration. Then use the material properties to obtain compensation values of the calibration part and the measured crankshaft part at different temperatures. Finally, the compensation parameters for displacement sensor can be obtained through the BP algorithm. The improved dragonfly algorithm (DA) is used to optimize the parameters of BP neural network algorithm. Experiments verify the effectiveness of IDA-BP for LVDT in temperature compensation. After temperature compensation, the error range of main journal radius is reduced from 0.0156 mm to 0.0028 mm, the residual error decreased from −0.0282 mm~+0.0018 mm to −0.0058 mm~−0.0008 mm. The influence of temperature changes on the measurement is reduced and measurement accuracy is improved through the temperature compensation method. The effectiveness of the method is proved.

scholarly journals A Concept of a Compact and Inexpensive Device for Controlling Weeds with Laser Beams

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1616
Author(s):  
Ildar Rakhmatulin ◽  
Christian Andreasen
Keyword(s):  
Neural Network ◽  
Decision Model ◽  
Control Device ◽  
Guidance System ◽  
Laser Beams ◽  
Laser Guidance ◽  
Couch Grass ◽  
Elytrigia Repens ◽  
Weed Plants ◽  
Plant Length

A prototype of a relatively cheap laser-based weeding device was developed and tested on couch grass (Elytrigia repens (L.) Desv. ex Nevski) mixed with tomatoes. Three types of laser were used (0.3 W, 1 W, and 5 W). A neural network was trained to identify the weed plants, and a laser guidance system estimated the coordinates of the weed. An algorithm was developed to estimate the energy necessary to harm the weed plants. We also developed a decision model for the weed control device. The energy required to damage a plant depended on the diameter of the plant which was related to plant length. The 1 W laser was not sufficient to eliminate all weed plants and required too long exposure time. The 5 W laser was more efficient but also harmed the crop if the laser beam became split into two during the weeding process. There were several challenges with the device, which needs to be improved upon. In particular, the time of exposure needs to be reduced significantly. Still, the research showed that it is possible to develop a concept for laser weeding using relatively cheap equipment, which can work in complicated situations where weeds and crop are mixed.

Development of new laser guidance system which improves accuracy of image-guided biopsy

1997 ◽  
Vol 4 (12) ◽  
pp. 844-845
Author(s):  
F. Scott Pereles ◽  
Evan C. Unger ◽  
Michael R. Baker ◽  
Elizabeth A. Krupinski
Keyword(s):  
Guidance System ◽  
Laser Guidance ◽  
Image Guided ◽  
Guided Biopsy

scholarly journals CIGuide: in situ augmented reality laser guidance

2019 ◽  
Vol 15 (1) ◽  
pp. 49-57
Author(s):  
Zoltán Bárdosi ◽  
Christian Plattner ◽  
Yusuf Özbek ◽  
Thomas Hofmann ◽  
Srdjan Milosavljevic ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Skull Base ◽  
Visual Cues ◽  
Needle Insertion ◽  
Guidance System ◽  
Laser Guidance ◽  
End Effector ◽  
Magnetic Tracking ◽  
Lateral Skull Base

Abstract Purpose  A robotic intraoperative laser guidance system with hybrid optic-magnetic tracking for skull base surgery is presented. It provides in situ augmented reality guidance for microscopic interventions at the lateral skull base with minimal mental and workload overhead on surgeons working without a monitor and dedicated pointing tools. Methods  Three components were developed: a registration tool (Rhinospider), a hybrid magneto-optic-tracked robotic feedback control scheme and a modified robotic end-effector. Rhinospider optimizes registration of patient and preoperative CT data by excluding user errors in fiducial localization with magnetic tracking. The hybrid controller uses an integrated microscope HD camera for robotic control with a guidance beam shining on a dual plate setup avoiding magnetic field distortions. A robotic needle insertion platform (iSYS Medizintechnik GmbH, Austria) was modified to position a laser beam with high precision in a surgical scene compatible to microscopic surgery. Results  System accuracy was evaluated quantitatively at various target positions on a phantom. The accuracy found is 1.2 mm ± 0.5 mm. Errors are primarily due to magnetic tracking. This application accuracy seems suitable for most surgical procedures in the lateral skull base. The system was evaluated quantitatively during a mastoidectomy of an anatomic head specimen and was judged useful by the surgeon. Conclusion  A hybrid robotic laser guidance system with direct visual feedback is proposed for navigated drilling and intraoperative structure localization. The system provides visual cues directly on/in the patient anatomy, reducing the standard limitations of AR visualizations like depth perception. The custom- built end-effector for the iSYS robot is transparent to using surgical microscopes and compatible with magnetic tracking. The cadaver experiment showed that guidance was accurate and that the end-effector is unobtrusive. This laser guidance has potential to aid the surgeon in finding the optimal mastoidectomy trajectory in more difficult interventions.

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